Botulinum toxin compositions

ABSTRACT

A high potency botulinum toxin pharmaceutical composition comprising two excipients (such as albumin and sodium chloride) in a weight to weight ratio of between about 1 and about 100.

CROSS REFERENCE

This application is a continuation of application Ser. No. 11/195,268filed Aug. 1, 2005, the entire contents of which application isincorporated herein by reference.

BACKGROUND

The present invention relates to improved botulinum toxin pharmaceuticalcompositions. In particular, the present invention relates to botulinumtoxin pharmaceutical compositions with an increased potency.

A pharmaceutical composition is a formulation which contains at leastone active ingredient (such as for example a Clostridial toxin, such asa botulinum neurotoxin) as well as, for example, one or more excipients,buffers, carriers, stabilizers, preservatives and/or bulking agents, andis suitable for administration to a patient to achieve a desired effector result. The pharmaceutical compositions disclosed herein can havediagnostic, therapeutic, cosmetic and/or research utility in variousspecies, such as for example in human patients or subjects.

For storage stability and convenience of handling, a pharmaceuticalcomposition can be formulated as a lyophilized (i.e. freeze dried) orvacuum dried powder which can be reconstituted with a suitable fluid,such as saline or water, prior to administration to a patient.Alternately, the pharmaceutical composition can be formulated as anaqueous solution or suspension. A pharmaceutical composition can containa proteinaceous active ingredient. Unfortunately, a protein activeingredient can be very difficult to stabilize (i.e. maintained in astate where loss of biological activity is minimized), resultingtherefore in a loss of protein and/or loss of protein activity duringthe formulation, reconstitution (if required) and during the period ofstorage prior to use of a protein containing pharmaceutical composition.Protein active ingredient stability problems can occur because ofdenaturation, degradation, dimerization, and/or polymerization of theprotein. Various excipients, such as albumins, gelatins, polysaccharidesand amino acids (native or recombinant) have been used with differingdegrees of success to try and stabilize a protein active ingredientpresent in a pharmaceutical composition. Additionally, cryoprotectantssuch as alcohols have been used to reduce protein denaturation under thefreezing conditions of lyophilization.

Albumins are small, abundant plasma proteins. Human serum albumin has amolecular weight of about 69 kiloDaltons (kD) and has been used as anon-active ingredient in a pharmaceutical composition where it can serveas a bulk carrier and stabilizer of certain protein active ingredientspresent in a pharmaceutical composition.

The stabilization function of albumin in a pharmaceutical compositioncan be present both during the multi-step formulation of thepharmaceutical composition and upon the later reconstitution of theformulated pharmaceutical composition. Thus, stability can be impartedby albumin to a proteinaceous active ingredient in a pharmaceuticalcomposition by, for example, (1) reducing adhesion (commonly referred toas “stickiness”) of the protein active ingredient to surfaces, such asthe surfaces of laboratory glassware, vessels, to the vial in which thepharmaceutical composition is reconstituted and to the inside surface ofa syringe used to inject the pharmaceutical composition. Adhesion of aprotein active ingredient to surfaces can lead to loss of activeingredient and to denaturation of the remaining retained protein activeingredient, both of which reduce the total activity of the activeingredient present in the pharmaceutical composition, and; (2) reducingdenaturation of the active ingredient which can occur upon preparationof a low dilution solution of the active ingredient.

As well as being able to stabilize a protein active ingredient in apharmaceutical composition, human serum albumin also has the advantageof generally negligible immunogenicity when injected into a humanpatient. A compound with an appreciable immunogenicity can cause theproduction of antibodies against it which can lead to an anaphylacticreaction and/or to the development of drug resistance, with the diseaseor disorder to be treated thereby becoming potentially refractory to thepharmaceutical composition which has an immunogenic component. Gelatinhas been used in some protein active ingredient pharmaceuticalcompositions as an albumin substitute.

Botulinum Toxin

The anaerobic, gram positive bacterium Clostridium botulinum produces apotent polypeptide neurotoxin, botulinum toxin, which causes aneuroparalytic illness in humans and animals referred to as botulism.Clostridium botulinum and its spores are commonly found in soil and thebacterium can grow in improperly sterilized and sealed food containersof home based canneries, which are the cause of many of the cases ofbotulism. The effects of botulism typically appear 18 to 36 hours aftereating the foodstuffs infected with a Clostridium botulinum culture orspores. The botulinum toxin can apparently pass unattenuated through thelining of the gut and attack peripheral motor neurons. Symptoms ofbotulinum toxin intoxication can progress from difficulty walking,swallowing, and speaking to paralysis of the respiratory muscles anddeath.

Botulinum toxin type A is the most lethal natural biological agent knownto man. About 50 picograms of botulinum toxin (purified neurotoxincomplex) type A is a LD₅₀ in mice. Interestingly, on a molar basis,botulinum toxin type A is 1.8 billion times more lethal than diphtheria,600 million times more lethal than sodium cyanide, 30 million times morelethal than cobrotoxin and 12 million times more lethal than cholera.Singh, Critical Aspects of Bacterial Protein Toxins, pages 63-84(chapter 4) of Natural Toxins II, edited by B. R. Singh et al., PlenumPress, New York (1976) (where the stated LD₅₀ of botulinum toxin type Aof 0.3 ng equals 1 U is corrected for the fact that about 0.05 ng ofBOTOX® equals 1 unit). One unit (U) of botulinum toxin is defined as theLD₅₀ upon intraperitoneal injection into female Swiss Webster miceweighing 18-20 grams each. In other words, one unit of botulinum toxinis the amount of botulinum toxin that kills 50% of a group of femaleSwiss Webster mice. Seven generally immunologically distinct botulinumneurotoxins have been characterized, these being respectively botulinumneurotoxin serotypes A, B, C₁, D, E, F, and G, each of which isdistinguished by neutralization with type-specific antibodies. Thedifferent serotypes of botulinum toxin vary in the animal species thatthey affect and in the severity and duration of the paralysis theyevoke. For example, it has been determined that botulinum toxin type Ais 500 times more potent, as measured by the rate of paralysis producedin the rat, than is botulinum toxin type B. Additionally, botulinumtoxin type B has been determined to be non-toxic in primates at a doseof 480 U/kg which is about 12 times the primate LD₅₀ for botulinum toxintype A. The botulinum toxins apparently bind with high affinity tocholinergic motor neurons, are translocated into the neuron and blockthe presynaptic release of acetylcholine.

Botulinum toxins have been used in clinical settings for the treatmentof neuromuscular disorders characterized by hyperactive skeletalmuscles. Botulinum toxin type A was approved by the U.S. Food and DrugAdministration in 1989 for the treatment of essential blepharospasm,strabismus and hemifacial spasm in patients over the age of twelve.Clinical effects of peripheral injection (i.e. intramuscular orsubcutaneous) botulinum toxin type A are usually seen within one week ofinjection, and often within a few hours after injection. The typicalduration of symptomatic relief (i.e. flaccid muscle paralysis) from asingle intramuscular injection of botulinum toxin type A can be aboutthree months to about six months.

Although all the botulinum toxins serotypes apparently inhibit releaseof the neurotransmitter acetylcholine at the neuromuscular junction,they do so by affecting different neurosecretory proteins and/orcleaving these proteins at different sites. Botulinum toxin A is a zincendopeptidase which can specifically hydrolyze a peptide linkage of theintracellular, vesicle associated protein SNAP-25. Botulinum type E alsocleaves the 25 kiloDalton (kD) synaptosomal associated protein(SNAP-25), but targets different amino acid sequences within thisprotein, as compared to botulinum toxin type A. Botulinum toxin types B,D, F and G act on vesicle-associated protein (VAMP, also calledsynaptobrevin), with each serotype cleaving the protein at a differentsite. Finally, botulinum toxin type C₁ has been shown to cleave bothsyntaxin and SNAP-25. These differences in mechanism of action mayaffect the relative potency and/or duration of action of the variousbotulinum toxin serotypes.

Regardless of serotype, the molecular mechanism of toxin intoxicationappears to be similar and to involve at least three steps or stages. Inthe first step of the process, the toxin binds to the presynapticmembrane of the target neuron through a specific interaction between theheavy chain (H chain) and a cell surface receptor; the receptor isthought to be different for each serotype of botulinum toxin and fortetanus toxin. The carboxyl end segment of the H chain, H_(C), appearsto be important for targeting of the toxin to the cell surface.

In the second step, the toxin crosses the plasma membrane of thepoisoned cell. The toxin is first engulfed by the cell throughreceptor-mediated endocytosis, and an endosome containing the toxin isformed. The toxin then escapes the endosome into the cytoplasm of thecell. This last step is thought to be mediated by the amino end segmentof the H chain, H_(N), which triggers a conformational change of thetoxin in response to a pH of about 5.5 or lower. Endosomes are known topossess a proton pump which decreases intra endosomal pH. Theconformational shift exposes hydrophobic residues in the toxin, whichpermits the toxin to embed itself in the endosomal membrane. The toxinthen translocates through the endosomal membrane into the cytosol.

The last step of the mechanism of botulinum toxin activity appears toinvolve reduction of the disulfide bond joining the H and L chain. Theentire toxic activity of botulinum and tetanus toxins is contained inthe L chain of the holotoxin; the L chain is a zinc (Zn++) endopeptidasewhich selectively cleaves proteins essential for recognition and dockingof neurotransmitter-containing vesicles with the cytoplasmic surface ofthe plasma membrane, and fusion of the vesicles with the plasmamembrane. Tetanus neurotoxin, botulinum toxin B, D, F, and G causedegradation of synaptobrevin (also called vesicle-associated membraneprotein (VAMP)), a synaptosomal membrane protein. Most of the VAMPpresent at the cytosolic surface of the synaptic vesicle is removed as aresult of any one of these cleavage events. Each toxin specificallycleaves a different bond.

The molecular weight of the botulinum toxin protein molecule, for allseven of the known botulinum toxin serotypes, is about 150 kD.Interestingly, the botulinum toxins are released by Clostridialbacterium as complexes comprising the 150 kD botulinum toxin proteinmolecule along with associated non-toxin proteins. Thus, the botulinumtoxin type A complex can be produced by Clostridial bacterium as 900 kD,500 kD and 300 kD forms. Botulinum toxin types B and C₁ are apparentlyproduced as only a 500 kD complex. Botulinum toxin type D is produced asboth 300 kD and 500 kD complexes. Finally, botulinum toxin types E and Fare produced as only approximately 300 kD complexes. The complexes (i.e.molecular weight greater than about 150 kD) are believed to contain anon-toxin hemagglutinin protein and a non-toxin and non-toxicnonhemagglutinin protein. These two non-toxin proteins (which along withthe botulinum toxin molecule can comprise the relevant neurotoxincomplex) may act to provide stability against denaturation to thebotulinum toxin molecule and protection against digestive acids whentoxin is ingested. Additionally, it is possible that the larger (greaterthan about 150 kD molecular weight) botulinum toxin complexes may resultin a slower rate of diffusion of the botulinum toxin away from a site ofintramuscular injection of a botulinum toxin complex. The toxincomplexes can be dissociated into toxin protein and hemagglutininproteins by treating the complex with red blood cells at pH 7.3. Thetoxin protein has a marked instability upon removal of the hemagglutininprotein.

All the botulinum toxin serotypes are made by Clostridium botulinumbacteria as inactive single chain proteins which must be cleaved ornicked by proteases to become neuroactive. The bacterial strains thatmake botulinum toxin serotypes A and G possess endogenous proteases andserotypes A and G can therefore be recovered from bacterial cultures inpredominantly their active form. In contrast, botulinum toxin serotypesC₁, D, and E are synthesized by nonproteolytic strains and are thereforetypically unactivated when recovered from culture. Serotypes B and F areproduced by both proteolytic and nonproteolytic strains and thereforecan be recovered in either the active or inactive form. However, eventhe proteolytic strains that produce, for example, the botulinum toxintype B serotype only cleave a portion of the toxin produced. The exactproportion of nicked to unnicked molecules depends on the length ofincubation and the temperature of the culture. Therefore, a certainpercentage of any preparation of, for example, the botulinum toxin typeB toxin is likely to be inactive, possibly accounting for the knownsignificantly lower potency of botulinum toxin type B as compared tobotulinum toxin type A. The presence of inactive botulinum toxinmolecules in a clinical preparation will contribute to the overallprotein load of the preparation, which has been linked to increasedantigenicity, without contributing to its clinical efficacy.Additionally, it is known that botulinum toxin type B has, uponintramuscular injection, a shorter duration of activity and is also lesspotent than botulinum toxin type A at the same dose level.

In vitro studies have indicated that botulinum toxin inhibits potassiumcation induced release of both acetylcholine and norepinephrine fromprimary cell cultures of brainstem tissue. Additionally, it has beenreported that botulinum toxin inhibits the evoked release of bothglycine and glutamate in primary cultures of spinal cord neurons andthat in brain synaptosome preparations botulinum toxin inhibits therelease of each of the neurotransmitters acetylcholine, dopamine,norepinephrine, CGRP and glutamate.

High quality crystalline botulinum toxin type A can be produced from theHall A strain of Clostridium botulinum with characteristics of ≧3×10⁷U/mg, an A₂₆₀/A₂₇₈ of less than 0.60 and a distinct pattern of bandingon gel electrophoresis. The known Schantz process can be used to obtaincrystalline botulinum toxin type A, as set forth in Schantz, E. J., etal, Properties and use of Botulinum toxin and Other MicrobialNeurotoxins in Medicine, Microbiol Rev. 56: 80-99 (1992). Generally, thebotulinum toxin type A complex can be isolated and purified from ananaerobic fermentation by cultivating Clostridium botulinum type A in asuitable medium. Raw toxin can be harvested by precipitation withsulfuric acid and concentrated by ultramicrofiltration. Purification canbe carried out by dissolving the acid precipitate in calcium chloride.The toxin can then be precipitated with cold ethanol. The precipitatecan be dissolved in sodium phosphate buffer and centrifuged. Upon dryingthere can then be obtained approximately 900 kD crystalline botulinumtoxin type A complex with a specific potency of 3×10⁷ LD₅₀ U/mg orgreater. This known process can also be used, upon separation out of thenon-toxin proteins, to obtain pure botulinum toxins, such as forexample: purified botulinum toxin type A with an approximately 150 kDmolecular weight with a specific potency of 1−2×10⁸ LD₅₀ U/mg orgreater; purified botulinum toxin type B with an approximately 156 kDmolecular weight with a specific potency of 1−2×10⁸ LD₅₀ U/mg orgreater, and; purified botulinum toxin type F with an approximately 155kD molecular weight with a specific potency of 1−2×10⁷ LD₅₀ U/mg orgreater.

A pure (i.e. 150 kDa botulinum toxin free of the non-toxin complexproteins) can be obtained by loading a solution of a botulinum toxincomplex onto a suitable ion exchange chromatograph in a pH 8 buffer todisassociate the non toxin complex proteins from the 150 kDa botulinumtoxin molecule, thereby providing (in the flow through from the column)a solution of a botulinum toxin neurotoxic component with anapproximately 150 kD molecular weight.

Pure botulinum toxin (i.e. the approximately 150 kDa molecular weightneurotoxic component of a botulinum toxin complex) has been used totreat humans. See e.g. Kohl A., et al., Comparison of the effect ofbotulinum toxin A (Botox (R)) with the highly-purified neurotoxin (NT201) in the extensor digitorum brevis muscle test, Mov Disord 2000;15(Suppl 3):165. Hence, a botulinum toxin pharmaceutical composition canbe prepared using a pure (approx 150 kDa) botulinum toxin, as opposed touse of a botulinum toxin complex. A pure botulinum toxin type A isavailable from Merz Pharmaceuticals under the tradename XEOMIN.

Already prepared and purified botulinum toxins and toxin complexessuitable for preparing pharmaceutical formulations can be obtained fromList Biological Laboratories, Inc., Campbell, Calif.; the Centre forApplied Microbiology and Research, Porton Down, U.K.; Wako (Osaka,Japan), as well as from Sigma Chemicals of St Louis, Mo.

Examples of clinical use of a botulinum toxin are:

(1) about 75-125 units of BOTOX®¹ per intramuscular injection (multiplemuscles) to treat cervical dystonia; 1Available from Allergan, Inc., ofIrvine, Calif. under the tradename BOTOX®.(2) 5-10 units of BOTOX® per intramuscular injection to treat glabellarlines (brow furrows) (5 units injected intramuscularly into the procerusmuscle and 10 units injected intramuscularly into each corrugatorsupercilii muscle);(3) about 30-80 units of BOTOX® to treat constipation by intrasphincterinjection of the puborectalis muscle;(4) about 1-5 units per muscle of intramuscularly injected BOTOX® totreat blepharospasm by injecting the lateral pre-tarsal orbicularisoculi muscle of the upper lid and the lateral pre-tarsal orbicularisoculi of the lower lid.(5) to treat strabismus, extraocular muscles have been injectedintramuscularly with between about 1-5 units of BOTOX®, the amountinjected varying based upon both the size of the muscle to be injectedand the extent of muscle paralysis desired (i.e. amount of dioptercorrection desired).(6) to treat upper limb spasticity following stroke by intramuscularinjections of BOTOX® into five different upper limb flexor muscles, asfollows:

(a) flexor digitorum profundus: 7.5 U to 30 U

(b) flexor digitorum sublimus: 7.5 U to 30 U

(c) flexor carpi ulnaris: 10 U to 40 U

(d) flexor carpi radialis: 15 U to 60 U

(e) biceps brachii: 50 U to 200 U. Each of the five indicated muscleshas been injected at the same treatment session, so that the patientreceives from 90 U to 360 U of upper limb flexor muscle BOTOX® byintramuscular injection at each treatment session.

(7) to treat migraine, pericranial injected (injected symmetrically intoglabellar, frontalis and temporalis muscles) injection of 25 U of BOTOX®has showed significant benefit as a prophylactic treatment of migrainecompared to vehicle as measured by decreased measures of migrainefrequency, maximal severity, associated vomiting and acute medicationuse over the three month period following the 25 U injection.

It is known that botulinum toxin type A can have an efficacy for up to12 months (European J. Neurology 6 (Supp 4): S111-S1150: 1999), and insome circumstances for as long as 27 months. The Laryngoscope109:1344-1346: 1999. However, the usual duration of the effect of anintramuscular injection of Botox® is typically about 3 to 4 months.

The success of botulinum toxin type A to treat a variety of clinicalconditions has led to interest in other botulinum toxin serotypes.European patent EPI 112082 (“Stable liquid formulations of botulinumtoxin”), issued Jul. 31, 2002 claims a stable liquid pharmaceuticalbotulinum toxin formulation comprising a buffer (pH 5-6) and a botulinumtoxin, wherein the toxin formulation is stable as a liquid for at leastone year at temperatures between 0-10 C or at least 6 months attemperatures between 10 and 30 C. Such a botulinum toxin pharmaceuticalformulation (an embodiment of which is sold commercially under thetradename MyoBloc® or NeuroBloc® by Solstice Neurosciences, Inc., of SanDiego, Calif.) is prepared as a liquid solution (no lyophilization orvacuum drying is carried out) which does not require reconstitutionbefore use.

Chinese patent application CN 1215084A discusses an albumin freebotulinum toxin type A formulated with gelatin, an animal derivedprotein. U.S. Pat. No. 6,087,327 also discloses a composition ofbotulinum toxin types A and B formulated with gelatin.

U.S. Pat. No. 5,512,547 (Johnson et al) entitled “PharmaceuticalComposition of Botulinum Neurotoxin and Method of Preparation” issuedApr. 30, 1996 and claims a pure botulinum type A formulation comprisingalbumin and trehalose, storage stable at 37 degrees C.

U.S. Pat. No. 5,756,468 (Johnson et al) issued May 26, 1998(“Pharmaceutical Compositions of Botulinum Toxin or Botulinum Neurotoxinand Method of Preparation”), and claims a lyophilized botulinum toxinformulation comprising a thioalkyl, albumin and trehalose which can bestored between 25 degrees C. and 42 degrees C.

U.S. Pat. No. 5,696,077 (Johnson et al) entitled “PharmaceuticalComposition Containing Botulinum B Complex” issued Dec. 9, 1997 andclaims a freeze dried, sodium chloride-free botulinum type B complexformation comprising a type B complex and a protein excipient.

U.S. patent application publication number 2003 0118598 (Hunt) disclosesuses of various excipients such as a recombinant albumin, collagen or astarch to stabilize a botulinum toxin.

Goodnough M. C., et al., Stabilization of botulinum toxin type A duringlyophilization, Appl Environ Microbiol 1992; 58(10):3426-3428, and;Goodnough M. C., et al., Recovery of type-A botulinal toxin followinglyophilization, Acs Symposium Series 1994; 567(−):193-203, disclosebotulinum toxin formulations comprising albumin and sodium chloride in aratio of about 0.6:1 (i.e. 5 mg of BSA or HSA per ml and 9 mg of NaClper ml of reconstituted botulinum toxin solution) and state thatelimination of sodium chloride from the botulinum toxin formulation (andincreasing the HSA to as much as 9 mg/ml in the salt free formulations)contributed significantly to obtaining a formulation with activebotulinum toxin.

The botulinum toxin molecule (about 150 kDa), as well as the botulinumtoxin complexes (about 300-900 kDa), such as the toxin type A complexare extremely susceptible to denaturation due to surface denaturation,heat, and alkaline conditions. Inactivated toxin forms toxoid proteinswhich may be immunogenic. The resulting antibodies can render a patientrefractory to toxin injection.

As with enzymes generally, the biological activities of the botulinumtoxins (which are intracellular peptidases) are dependant, at least inpart, upon their three dimensional conformation. Thus, botulinum toxintype A is detoxified by heat, various chemicals surface stretching andsurface drying. Additionally, it is known that dilution of the toxincomplex obtained by the known culturing, fermentation and purificationto the much, much lower toxin concentrations used for pharmaceuticalcomposition formulation results in rapid detoxification of the toxinunless a suitable stabilizing agent is present. Dilution of the toxinfrom milligram quantities to a solution containing nanograms permilliliter presents significant difficulties because of the rapid lossof specific toxicity upon such great dilution. Since the botulinum toxinmay be used months or years after the botulinum toxin containingpharmaceutical composition is formulated, the botulinum toxin must bestabilized with a stabilizing agent, such as an albumin or gelatin.Additionally, for storage stability botulinum toxin can be processedinto a solid state (i.e. a powder) by known lyophilization orvacuum-drying techniques.

Furthermore, any one of the harsh pH, temperature and concentrationrange conditions required to lyophilize (freeze-dry) or vacuum dry abotulinum toxin containing pharmaceutical composition into a toxinshipping and storage format (ready for use or reconstitution by aphysician) can detoxify the toxin. Thus, gelatin and serum albumin havebeen used with some success to stabilize botulinum toxin.

A commercially available botulinum toxin containing pharmaceuticalcomposition is sold under the trademark BOTOX® (available from Allergan,Inc., of Irvine, Calif.). BOTOX® consists of a purified botulinum toxintype A complex, human serum albumin, and sodium chloride packaged insterile, vacuum-dried form. The botulinum toxin type A is made from aculture of the Hall strain of Clostridium botulinum grown in a mediumcontaining N—Z amine and yeast extract. The botulinum toxin type Acomplex is purified from the culture solution by a series of acidprecipitations to a crystalline complex consisting of the active highmolecular weight toxin protein and an associated hemagglutinin protein.The crystalline complex is re-dissolved in a solution containing salineand albumin and sterile filtered (0.2 microns) prior to vacuum-drying.BOTOX® can be reconstituted with sterile, non-preserved saline prior tointramuscular injection. Each vial of BOTOX® contains about 100 units(U) of Clostridium botulinum toxin type A complex, 0.5 milligrams ofhuman serum albumin and 0.9 milligrams of sodium chloride in a sterile,vacuum-dried form without a preservative.

To reconstitute vacuum-dried BOTOX® sterile normal saline without apreservative (0.9% Sodium Chloride injection) is used by drawing up theproper amount of diluent in the appropriate size syringe. Since BOTOX®is denatured by bubbling or similar violent agitation, the diluent isgently injected into the vial. For sterility reasons, BOTOX® should beadministered within about 72 hours after reconstitution. During thistime period, reconstituted BOTOX® is stored in a refrigerator (2° to 8°C.). Reconstituted BOTOX® is clear, colorless and free of particulatematter. The vacuum-dried product is stored in a freezer or refrigerator.

Other commercially available botulinum toxin containing pharmaceuticalcompositions include Dysport® (Clostridium botulinum type A toxinhemagglutinin complex with human serum albumin and lactose in theformulation, available from Ipsen Limited, Berkshire, U.K. as a powderto be reconstituted with 0.9% sodium chloride before use), and MyoBloc™(an injectable solution comprising botulinum toxin type B, human serumalbumin, sodium succinate, and sodium chloride at about pH 5.6,available from Elan Corporation, Dublin, Ireland).

It has been reported that a suitable alternative to human serum albuminas a botulinum toxin stabilizer may be another protein or alternativelya low molecular weight (non-protein) compound. Carpender et al.,Interactions of Stabilizing Additives with Proteins DuringFreeze-Thawing and Freeze-Drying, International Symposium on BiologicalProduct Freeze-Drying and Formulation, 24-26 Oct. 1990; Karger (1992),225-239.

Human serum albumin is believed to function in a pharmaceuticalcomposition as more than a mere bulking agent. Thus, albumin apparentlycan interact with botulinum toxin so as to increase the potency of theneurotoxin. For example, it is known that bovine serum albumin can actas more than a mere stabilizing excipient for botulinum toxin type A,since bovine serum albumin apparently also accelerates the rate ofcatalysis of synthetic peptide substrates, which substrates resemble theSNAP-25 intraneuronal substrate for botulinum toxin type A Schmidt, etal., Endoproteinase Activity of Type A Botulinum Neurotoxin SubstrateRequirements and Activation by Serum Albumin, J. of Protein Chemistry,16 (1), 19-26 (1997). Thus, albumin may have a potentiating effect,apparently by affecting rate kinetics, upon the intracellularproteolytic action of a botulinum toxin upon the toxin's substrate. Thispotentiating effect may be due to albumin which has accompanied thebotulinum toxin upon endocytosis of the toxin into a target neuron orthe potentiating effect may be due to the pre-existing presencecytoplasmic albumin within the neuron protein prior to endocytosis ofthe botulinum toxin.

Acetylcholine

Typically only a single type of small molecule neurotransmitter isreleased by each type of neuron in the mammalian nervous system. Theneurotransmitter acetylcholine is secreted by neurons in many areas ofthe brain, but specifically by the large pyramidal cells of the motorcortex, by several different neurons in the basal ganglia, by the motorneurons that innervate the skeletal muscles, by the preganglionicneurons of the autonomic nervous system (both sympathetic andparasympathetic), by the postganglionic neurons of the parasympatheticnervous system, and by some of the postganglionic neurons of thesympathetic nervous system. Essentially, only the postganglionicsympathetic nerve fibers to the sweat glands, the piloerector musclesand a few blood vessels are cholinergic as most of the postganglionicneurons of the sympathetic nervous system secret the neurotransmitternorepinephrine. In most instances acetylcholine has an excitatoryeffect. However, acetylcholine is known to have inhibitory effects atsome of the peripheral parasympathetic nerve endings, such as inhibitionof heart rate by the vagal nerve.

The efferent signals of the autonomic nervous system are transmitted tothe body through either the sympathetic nervous system or theparasympathetic nervous system. The preganglionic neurons of thesympathetic nervous system extend from preganglionic sympathetic neuroncell bodies located in the intermediolateral horn of the spinal cord.The preganglionic sympathetic nerve fibers, extending from the cellbody, synapse with postganglionic neurons located in either aparavertebral sympathetic ganglion or in a prevertebral ganglion. Since,the preganglionic neurons of both the sympathetic and parasympatheticnervous system are cholinergic, application of acetylcholine to theganglia will excite both sympathetic and parasympathetic postganglionicneurons.

Acetylcholine activates two types of receptors, muscarinic and nicotinicreceptors. The muscarinic receptors are found in all effector cellsstimulated by the postganglionic, neurons of the parasympathetic nervoussystem as well as in those stimulated by the postganglionic cholinergicneurons of the sympathetic nervous system. The nicotinic receptors arefound in the adrenal medulla, as well as within the autonomic ganglia,that is on the cell surface of the postganglionic neuron at the synapsebetween the preganglionic and postganglionic neurons of both thesympathetic and parasympathetic systems. Nicotinic receptors are alsofound in many nonautonomic nerve endings, for example in the membranesof skeletal muscle fibers at the neuromuscular junction.

Acetylcholine is released from cholinergic neurons when small, clear,intracellular vesicles fuse with the presynaptic neuronal cell membrane.A wide variety of non-neuronal secretory cells, such as, adrenal medulla(as well as the PC12 cell line) and pancreatic islet cells releasecatecholamines and parathyroid hormone, respectively, from largedense-core vesicles. The PC12 cell line is a clone of ratpheochromocytoma cells extensively used as a tissue culture model forstudies of sympathoadrenal development. Botulinum toxin inhibits therelease of both types of compounds from both types of cells in vitro,permeabilized (as by electroporation) or by direct injection of thetoxin into the denervated cell. Botulinum toxin is also known to blockrelease of the neurotransmitter glutamate from cortical synaptosomescell cultures.

A neuromuscular junction is formed in skeletal muscle by the proximityof axons to muscle cells. A signal transmitted through the nervoussystem results in an action potential at the terminal axon, withactivation of ion channels and resulting release of the neurotransmitteracetylcholine from intraneuronal synaptic vesicles, for example at themotor endplate of the neuromuscular junction. The acetylcholine crossesthe extracellular space to bind with acetylcholine receptor proteins onthe surface of the muscle end plate. Once sufficient binding hasoccurred, an action potential of the muscle cell causes specificmembrane ion channel changes, resulting in muscle cell contraction. Theacetylcholine is then released from the muscle cells and metabolized bycholinesterases in the extracellular space. The metabolites are recycledback into the terminal axon for reprocessing into further acetylcholine.

Thus, what is needed is a process for preparing a botulinum toxinpharmaceutical formulation where little or no botulinum toxin is lostduring the compounding process. Alternately stated, what is needed is aprocess for preparing a botulinum toxin pharmaceutical formulation whichpermits a high recovery of the botulinum toxin after reconstitution.Loss of botulinum toxin during compounding (which leads to a lowerrecovery) presents the possibility of inactivated toxin (toxoid) beingpresent in the final reconstituted product, thereby raising an antigenicpotential of the product upon administration to a patient. Thetheoretical optimal is to have 100% of the botulinum toxin which entersthe compounding process present in the final reconstituted product andpresent as biologically active botulinum toxin.

What is also needed therefore is a botulinum toxin containingpharmaceutical composition with a higher potency, as compared to thepotencies of known botulinum toxin pharmaceutical compositions.Expressed in an alternate manner, what is needed is a botulinum toxinpharmaceutical composition with a higher potency of the botulinum toxinfor each nanogram of the botulinum toxin present in the botulinum toxinpharmaceutical composition.

SUMMARY

The present invention meets this need by providing a process forpreparing a botulinum toxin pharmaceutical formulation wherein little orno botulinum toxin is lost during the compounding process. Alternatelystated, a process within the scope of the present invention permitspreparation of a botulinum toxin pharmaceutical formulation with a highrecovery of the botulinum toxin after reconstitution. Significantly,processes within the scope of the present invention approach thetheoretical optimum by permitting about 100% of the botulinum toxinwhich enters the compounding process to be present in the finalreconstituted product as biologically active botulinum toxin.

Additionally the present invention meets the needs expressed above byproviding a botulinum toxin pharmaceutical composition with a higher(that is an increased) potency, as compared to the potencies of knownbotulinum toxin pharmaceutical compositions. In particular, the presentinvention meets this need by providing a powdered (due for example tofreeze drying, lyophilization and/or vacuum drying) botulinum toxinpharmaceutical composition which upon (i.e. after) reconstitution withan aqueous fluid (such as saline or water) has an increased potency (asdetermined for example by the mouse LD₅₀ assay), as compared to thepotency after reconstitution with an aqueous fluid of a known powderedbotulinum toxin pharmaceutical composition (such as Botox® or Dysport®).Potency upon reconstitution can be referred to as potency after“recovery”. Hence, the present invention includes a botulinum toxinpharmaceutical composition with an increased potency upon recovery, orsynonymously with an increased recovered or recovery potency.

Briefly, an important aspect of the present invention for meeting thesedual needs of a high conservation (i.e. low or small loss) of the amountof the botulinum toxin which enters a compounding process (as comparedto the amount of active botulinum toxin present in the final[compounded] product), and a high botulinum toxin pharmaceuticalcomposition recovered potency, is achieved by compounding the solid formbotulinum toxin pharmaceutical composition such that two of theexcipients present in the botulinum toxin pharmaceutical composition arepresent, at least during the compounding process, in a particular weightto weight ratio or in a particular weight to weight ratio range.

DEFINITIONS

As used herein, the words or terms set forth below have the followingdefinitions.

“About” means that the item, parameter or term so qualified encompassesa range of plus or minus ten percent above and below the value of thestated item, parameter or term.

“Administration”, or “to administer” means the step of giving (i.e.administering) a pharmaceutical composition to a subject. Thepharmaceutical compositions disclosed herein are “locally administered”.Systemic (i.e. intravenous or oral) routes of administration areexcluded from the scope of the present invention, to the extent that asystemic administration would result in systemic effects of asystemically administered active ingredient. Systemic administration ofa targeted active ingredient which does not result in systemic effectsis not excluded from the scope of the present invention (see e.g.published U.S. patent applications 20040086532 and 20040086531). Localadministration includes, but is not limited to, intramuscular (i.m.)administration, intradermal or subdermal administration, subcutaneousadministration, intrathecal administration, intraperitoneal (i.p.)administration, topical contact, and implantation of a slow-releasedevice such as polymeric implant or miniosmotic pump.

“Botulinum toxin” means a neurotoxin produced by Clostridium botulinum,as well as a botulinum toxin (or the light chain or the heavy chainthereof) made recombinantly by a non-Clostridial species. The phrase“botulinum toxin”, as used herein, encompasses the botulinum toxinserotypes A, B, C, D, E, F and G. Botulinum toxin, as used herein, alsoencompasses both a botulinum toxin complex (i.e. the 300, 600 and 900kDa complexes) as well as the purified botulinum toxin (i.e. about 150kDa). “Purified (or pure) botulinum toxin” is defined as a botulinumtoxin that is isolated, or substantially isolated, from other proteins,including proteins that form a botulinum toxin complex. A purified (orpure) botulinum toxin can be greater than 95% pure, and preferably isgreater than 99% pure.

“Clostridial neurotoxin” means a neurotoxin produced from, or native to,a Clostridial bacterium, such as Clostridium botulinum, Clostridiumbutyricum or Clostridium beratti, as well as a Clostridial neurotoxinmade recombinantly by a non-Clostridial species.

“Enhanced potency” with regard to a botulinum toxin containingpharmaceutical composition means that the composition has a potency (asdetermined, for example, by the mouse LD₅₀ assay) which is from at least5% and up to 50%, or more, greater than the potency of a referencebotulinum toxin pharmaceutical composition. A reference botulinum toxinpharmaceutical composition can contain a botulinum toxin, sodiumchloride and HSA, wherein the albumin and the sodium chloride arepresent in a weight to weight ratio of about 0.6:1.

“Entirely free (i.e. “consisting of” terminology) means that within thedetection range of the instrument or process being used, the substancecannot be detected or its presence cannot be confirmed.

“Essentially free” (or “consisting essentially of”) means that onlytrace amounts of the substance can be detected.

“Excipient” means a substance present in a pharmaceutical compositionother than the active pharmaceutical ingredient present in thepharmaceutical composition. An excipient can be a buffer, carrier,stabilizer, preservative, diluent, vehicle, and/or a bulking agent, suchas an albumin, gelatin, collagen and/or sodium chloride.

“Immobilizing” means a step that prevents a subject from moving one ormore body parts. If a sufficient number of body parts are immobilized,the subject will accordingly be immobilized. Thus, “immobilizing”encompasses the immobilization of a body part, such as a limb, and/orthe complete immobilization of a subject.

“Modified botulinum toxin” means a botulinum toxin that has had at leastone of its amino acids deleted, modified, or replaced, as compared to anative botulinum toxin. Additionally, the modified botulinum toxin canbe a recombinantly produced neurotoxin, or a derivative or fragment of arecombinantly made neurotoxin. A modified botulinum toxin retains atleast one biological activity of the native botulinum toxin, such as,the ability to bind to a botulinum toxin receptor, or the ability toinhibit neurotransmitter release from a neuron. One example of amodified botulinum toxin is a botulinum toxin that has a light chainfrom one botulinum toxin serotype (such as serotype A), and a heavychain from a different botulinum toxin serotype (such as serotype B).Another example of a modified botulinum toxin is a botulinum toxincoupled to a neurotransmitter, such as substance P.

“Patient” means a human or non-human subject receiving medical orveterinary care. Accordingly, as disclosed herein, the compositions maybe used in treating any animal, such as mammals.

“Pharmaceutical composition” means a formulation in which an activeingredient can be a neurotoxin, such as a Clostridial neurotoxin. Theword “formulation” means that there is at least one additionalingredient in the pharmaceutical composition besides a neurotoxin activeingredient. A pharmaceutical composition is therefore a formulationwhich is suitable for diagnostic, therapeutic or cosmetic use (i.e. byintramuscular or subcutaneous injection or by insertion of a depot orimplant) to a subject, such as a human patient. The pharmaceuticalcomposition can be: in a lyophilized or vacuum dried condition; asolution formed after reconstitution of the lyophilized or vacuum driedpharmaceutical composition with saline or water, or; as a solution whichdoes not require reconstitution. The neurotoxin active ingredient can beone of the botulinum toxin serotypes A, B, C₁, D, E, F or G or a tetanustoxin, all of which can be made natively by Clostridial bacteria. Asstated, a pharmaceutical composition can be liquid or solid, for examplevacuum-dried. The constituent ingredients of a pharmaceuticalcomposition can be included in a single composition (that is all theconstituent ingredients, except for any required reconstitution fluid,are present at the time of initial compounding of the pharmaceuticalcomposition) or as a two-component system, for example a vacuum-driedcomposition reconstituted with a diluent such as saline which diluentcontains an ingredient (such as water) not present in the initialcompounding of the pharmaceutical composition.

“Polysaccharide” means a polymer of more than two saccharide moleculemonomers, which monomers can be identical or different.

“Protein stabilizer” (or “primary stabilizer”) is a chemical agent thatassists to preserve or maintain the biological structure (i.e. the threedimensional conformation) and/or biological activity of a protein (suchas a Clostridial neurotoxin, such as a botulinum toxin). Stabilizers canbe proteins or polysaccharides. Examples of protein stabilizers includehydroxyethyl starch (hetastarch), serum albumin, gelatin, collagen, aswell as a recombinant albumin, gelatin or collagen. As disclosed herein,the primary stabilizer can be a synthetic agent that would not producean immunogenic response (or produces an attenuated immune response) in asubject receiving a composition containing the primary stabilizer. Inother embodiments of the invention, the protein stabilizers may beproteins from the same species of animal that is being administered theprotein. Additional stabilizers may also be included in a pharmaceuticalcomposition. These additional or secondary stabilizers may be used aloneor in combination with primary stabilizers, such as proteins andpolysaccharides. Exemplary secondary stabilizers include, but are notlimited to non-oxidizing amino acid derivatives (such as a tryptophanderivate, such as N-acetyl-tryptophan (“NAT”)), caprylate (i.e. sodiumcaprylate), a polysorbate (i.e. P80), amino acids, and divalent metalcations such as zinc. A pharmaceutical composition can also includepreservative agents such as benzyl alcohol, benzoic acid, phenol,parabens and sorbic acid. A “recombinant stabilizer” is a “primarystabilizer” made by recombinant means, such as for example, arecombinantly made albumin (such as a recombinantly made human serumalbumin), collagen, gelatin or a cresol, such as an M-cresol.

“Stabilizing”, “stabilizes”, or “stabilization” mean that apharmaceutical active ingredient (“PAI”) retains at least 20% and up to100% of its biological activity (which can be assessed as potency or astoxicity by an in vivo LD₅₀ or ED₅₀ measure) in the presence of acompound which is stabilizing, stabilizes or which providesstabilization to the PAI. For example, upon (1) preparation of serialdilutions from a bulk or stock solution, or (2) upon reconstitution withsaline or water of a lyophilized, or vacuum dried botulinum toxincontaining pharmaceutical composition which has been stored at or belowabout −2 degrees C. for between six months and four years, or (3) for anaqueous solution botulinum toxin containing pharmaceutical compositionwhich has been stored at between about 2 degrees and about 8 degrees C.for from six months to four years, the botulinum toxin present in thereconstituted or aqueous solution pharmaceutical composition has (in thepresence of a compound which is stabilizing, stabilizes or whichprovides stabilization to the PAI) greater than about 20% and up toabout 100% of the potency or toxicity that the biologically activebotulinum toxin had prior to being incorporated into the pharmaceuticalcomposition.

“Substantially free” means present at a level of less than one percentby weight of the pharmaceutical composition.

“Therapeutic formulation” means a formulation can be used to treat andthereby alleviate a disorder or a disease, such as a disorder or adisease characterized by hyperactivity (i.e. spasticity) of a peripheralmuscle.

A pharmaceutical composition within the scope of my invention cancomprise a Clostridial toxin, such as a botulinum toxin, and anexcipient which acts to stabilize the toxin A pharmaceutical compositionwithin the scope of my invention can also consist essentially of abotulinum toxin, and a stabilizer. Additionally, pharmaceuticalcomposition within the scope of my invention can consist of a botulinumtoxin, and a recombinant stabilizer.

The botulinum toxin can be present as a botulinum toxin complex (i.e. asan approximately 300 kiloDalton to about 900 kiloDalton complex,depending upon the particular botulinum toxin serotype used) or thebotulinum toxin can be is present as a pure or purified botulinum toxin(meaning present as the about 150 kiloDalton neurotoxic component of abotulinum toxin complex) which is free, substantially or essentiallyfree of any botulinum toxin complex protein (i.e. removed fromassociation the HA and NTNH proteins). Thus, as shown by FIG. 1, abotulinum toxin made naturally by the Clostridium botulinum bacterium istypically made as a complex comprising the botulinum toxin molecule (aprotein with a molecular weight of about 150 kiloDaltons) (also referredto as the neurotoxic component) and an array of non-toxic proteins(haemaglutinins and non-haemaglutinins) in a close, though non-covalentassociation with the neurotoxic component. Thus, as shown by FIG. 1,there can be up to about seven non-neurotoxic molecules (total weightabout 750 kDa) associated (non-covalently) with the (about 150 kDa)neurotoxic component to form a 900 kDa botulinum neurotoxin type Acomplex. In FIG. 1: HA=NTHA=a non-toxic haemaglutinin; LC=light chain(about 50 kDa); HC=heavy chain (about 100 kDa); —S—S—=the singledisulphide bond which joins the LC and the HC, and; Zn=a zinc atom(botulinum toxin is a zinc endopeptidase). Hence, LC plus HC is amolecule with a molecular weight of about 150 kDa, and this is theneurotoxic component of the (in the case of botulinum toxin type A) 900kDa complex.

Any recombinant stabilizer which is present in a pharmaceuticalcomposition within the scope of my invention can be a recombinantalbumin, a recombinant collagen, a recombinant gelatin and/or otherrecombinant primary stabilizer. The pharmaceutical composition can alsocomprise a secondary stabilizer, such as a metal (i.e. zinc) or NAT.

Significantly, a pharmaceutical composition within the scope of myinvention can have an enhanced potency or stability. By enhanced potencyit is meant that the potency of a first botulinum toxin pharmaceuticalcomposition is greater than the potency of a second botulinum toxinpharmaceutical composition. For example a first botulinum toxinpharmaceutical composition can have a particular ratio (such as 28:1) oftwo excipients (such as albumin and sodium chloride) present in thefirst composition. A second botulinum toxin pharmaceutical compositioncan have a known ratio (such as about 0.6:1) of the same two excipients(i.e. albumin and sodium chloride) present in the second composition.Potency and relative potencies can be determined by a method used todetermine a biological activity of a botulinum toxin, such as a mouseLD₅₀ assay. Generally, greater potency means that a lesser amount (i.e.fewer units) of a botulinum toxin pharmaceutical composition is requiredto paralyze a muscle. Preferably, a first botulinum toxin pharmaceuticalcomposition has at least a 5% greater potency (and as much as a 50%greater potency) than does the second botulinum toxin pharmaceuticalcomposition.

A pharmaceutical composition within the scope of the present inventioncan also include a neurotoxin, and a polysaccharide. The polysaccharidestabilizes the neurotoxin. The pharmaceutical compositions disclosedherein can have a pH of between about 5 and 7.3 when reconstituted orupon injection.

The pharmaceutical composition is suitable for administration to a humanpatent to achieve a therapeutic effect, and the neurotoxin can be one ofthe botulinum toxin serotypes A, B, C₁, D, E, F and G.

A further embodiment of the present invention is a method for using apharmaceutical composition, the method comprising the step of localadministration of the pharmaceutical composition to a patient to achievea therapeutic or cosmetic effect.

Particular Pharmaceutical Compositions

My invention encompasses a pharmaceutical composition comprising: (a) abotulinum toxin; (b) a first excipient, wherein the first excipient isan albumin, and;

(c) a second excipient,

(d) wherein the weight to weight ratio of the first excipient to thesecond excipient present in the pharmaceutial composition is greaterthan 0.6 and less than about 100. The potency of the botulinum toxin inthis pharmaceutical composition can be between about 5% greater andabout 200% greater than the potency of a botulinum toxin in a comparisonpharmaceutical composition. The comparison pharmaceutical compositioncan contain: (a) the same amount and type of botulinum toxin, and; (b)the same first and second excipients, as does the pharmaceuticalcomposition, and; (c) the first and second excipients can be are presentin the comparison pharmaceutical composition in a weight to weight ratioof 0.6 or less. Additionally, the potency of the botulinum toxin in thepharmaceutical composition can be between about 10% greater and about100% greater than the potency of the botulinum toxin in the comparisonpharmaceutical composition, In this pharmaceutical composition thebotulinum toxin is present as a botulinum toxin complex or the botulinumtoxin can be present as a pure botulinum toxin (i.e. as a neurotoxiccomponent with a molecular weight of about 150 kiloDaltons, and atsubstantially free of the botulinum toxin complex proteins).

The first excipient in the pharmaceutical composition can be a serumalbumin or a recombinant albumin. The second excipient in thepharmaceutical composition can be sodium chloride. The weight to weightratio of the first excipient to the second excipient present in thepharmaceutical composition is between about 1 and about 50.

A detailed embodiment of a pharmaceutical composition within the scopeof my invention can comprise: (a) between about 2.0×10⁻¹¹ grams andabout 3.5×10⁻¹¹ grams of a botulinum toxin type A for each unit ofbotulinum toxin present in the pharmaceutical composition, the unit ofthe botulinum toxin being determined by a mouse LD₅₀ potency assay; (b)an albumin, and (c) sodium chloride, (d) wherein the weight to weightratio of the albumin to the sodium chloride present in thepharmaceutical composition is greater than 0.6 and less than about 100.The potency of the botulinum toxin in the pharmaceutical composition canbe between about 5% greater and about 200% greater than the potency of abotulinum toxin in a comparison pharmaceutical composition, whichcomparison pharmaceutical composition contains (a) the same amount andtype of botulinum toxin, and (b) the same albumin and sodium chloride,as does the pharmaceutical composition of claim 10, and (c) the albuminand sodium chloride are present in the comparison pharmaceuticalcomposition in a weight to weight ratio of 0.6 or less. The potency ofthe botulinum toxin in the pharmaceutical composition can be betweenabout 10% greater and about 100% greater than the potency of thebotulinum toxin in the comparison pharmaceutical composition.Alternately, the weight to weight ratio of the albumin to the sodium,chloride present in the pharmaceutial composition can between about 1and about 50.

My invention also encompasses a process for making a pharmaceuticalcomposition by (a) combining about 2.5 ng of a botulinum toxin type Acomplex with an albumin and sodium chloride in a weight to weight ratioof the albumin to the sodium chloride in the pharmaceutical compositionof greater than 0.6 and less than about 100, to form a mixture, and; (b)vacuum drying the mixture, to thereby obtain a pharmaceuticalcomposition with a potency after reconstitution of between about 70units and about 130 units. This process can further comprise the step,before the vacuum drying step, of lyophilizing the mixture. A usefulpharmaceutical composition can be made by this process.

My invention also encompasses a pharmaceutical composition suitable foradministration to a human, comprising: (a) a botulinum toxin; (b) sodiumchloride, and; (b) a stabilizer, wherein the potency of the botulinumtoxin present in the pharmaceutical composition is about 40 units/ng.The weight to weight ratio of the albumin to the sodium chloride presentin this pharmaceutical composition can be greater than 0.6 and less thanabout 100. The stabilizer can be a recombinant stabilizer, such as arecombinant albumin, a recombinant collagen and/or a recombinantgelatin. The botulinum toxin can be selected from the group consistingof botulinum toxins types A, B, C, D, E, and F.

My invention also encompasses a pharmaceutical composition suitable foradministration to a human, comprising: (a) a botulinum toxin; (b) sodiumchloride, and; (b) an albumin, wherein the potency of the botulinumtoxin present in the pharmaceutical composition is between about 24units/ng and about 60 units/ng. The weight to weight ratio of thealbumin to the sodium chloride can be greater than 0.6 and less thanabout 100.

My invention also encompasses a pharmaceutical composition suitable foradministration to a human, comprising: (a) a botulinum toxin; (b) sodiumchloride, and;

(b) an albumin, wherein the weight to weight ratio of the albumin to thesodium chloride present in the pharmaceutical composition is betweenabout 1 and about 40 and the potency of the botulinum toxin present inthe pharmaceutical composition is between about 24 units/ng and about 60units/ng.

My invention also encompasses a process for making a botulinum toxinpharmaceutical composition which has a potency of between about 30 to 40units/ng and is suitable for administration to a human, the processcomprising the steps of: (a) adding a botulinum toxin type A complexwhich has a potency of between about 30-40 units/ng to albumin andsodium chloride in a weight to weight ratio of about 1 to about 40, toform a mixture; (b) vacuum drying or lyophilizing the mixture, and; (c)reconstituting the mixture with normal saline, to thereby obtain abotulinum toxin pharmaceutical composition which has a potency ofbetween about 30-40 units/ng.

Finally, my invention also encompasses a method for treating atherapeutic or cosmetic condition, the method comprising the step ofadministering to a mammal a botulinum toxin pharmaceutical compositionwhich has a potency of about 40 units/ng.

The foregoing methods may be practiced and the compositions made using acomposition that comprises a botulinum toxin type A. In otherembodiments of the invention, the foregoing methods may be practicedwith a composition that comprises botulinum toxin type B. In furtherembodiments of the invention, the methods may be practiced with acomposition that comprises a plurality of botulinum toxin serotypes,such as botulinum toxin serotypes selected from the group consisting ofbotulinum toxin serotypes A, B, C₁, D, E, F and G. In certainembodiments of the invention, purified botulinum toxins may be used. Inother embodiments, modified botulinum toxins may be used. Thecompositions used in the foregoing methods may also include one or moreamino acids in addition to the botulinum toxin and the polysaccharide.Embodiments of the invention disclosed herein can be administeredintramuscularly (into or to the vicinity of a striated, smooth orcardiac muscle), intradermally, topically, subcutaneously, into or tothe vicinity of a gland, into a lumen of the body (such as into abladder lumen) and/or intrathecally.

DRAWINGS

The following drawings illustrate aspects of my invention.

FIG. 1 is a diagramatic representation of a 900 kiloDalton botulinumtoxin complex.

FIG. 2 is a graph which shows the mouse LD₅₀ potency afterreconstitution (on the Y-axis) of lyophilized, vacuum-dried botulinumtoxin formulations made with 2.5 ng of botulinum toxin, 500μ of HSA andfrom zero to 10N (9000 μg) of NaCl.

FIG. 3 presents in three axes recovered potency data for a number ofexperimental botulinum toxin formulations. The X axis of FIG. 3represents the amount of sodium chloride (NaCl) present in experimentalor research vial preparations in multiples of the sodium chloridenormalized (N) against the 900 μg NaCl content in a 100 unit vial ofBotox®. Thus, the integer one on the X axis in FIG. 1 represents 900 μgof NaCl. The Y axis of FIG. 3 represents the amount of human serumalbumin (HSA) present in the same experimental vial preparations inmultiples of the HSA normalized against the 500 μg HSA content in a 100unit Vial of Botox®. Thus, the integer one on the Y axis in FIG. 3represents 500 μg of HSA. The Z axis of FIG. 3 represents the recoveredpotency of these vacuum-dried experimental botulinum toxin compositions,where each vial contained exactly the same amount of botulinum toxin(2.5 ng) and where each botulinum toxin pharmaceutical composition wasreconstituted with the same amount of normal saline, and it's potencyafter reconstitution determined by the mouse LD₅₀ assay.

DESCRIPTION

The present invention is based upon the discovery that a stablebotulinum toxin with an enhanced potency can be made with a particularratio of excipients in a botulinum toxin pharmaceutical composition.

I have discovered that the potency of a botulinum toxin in a botulinumtoxin pharmaceutical composition can be increased significantly byformulating the botulinum toxin pharmaceutical composition withparticular ratios of the excipients in the botulinum toxinpharmaceutical composition. Such particular excipient ratios permitobtaining a botulinum toxin pharmaceutical composition which has ahigher potency than does a botulinum toxin pharmaceutical compositionwith different excipient ratios. For example, my invention permits abotulinum toxin pharmaceutical composition to be prepared with a higherpotency per nanogram botulinum toxin present in the botulinum toxinpharmaceutical composition, than the potency of a botulinum toxinpharmaceutical composition with different excipient ratios.

The botulinum toxin present in the botulinum toxin pharmaceuticalcomposition can be a native, recombinant, hybrid, chimeric or modifiedbotulinum toxin type A, B, C, D, E, F or G. Additionally, the botulinumtoxin can be present in the botulinum toxin pharmaceutical compositionas either a complex or as a pure botulinum toxin. A botulinum toxincomplex comprises a botulinum toxin molecule (about 150 kDa) and one ormore non-toxic haemagluttinin and/or non-toxic non-haemagluttininproteins. The complex can have a molecular weight of, for example, 300,600 or 900 kDa, with the amount in excess of 150 kDa being attributed tothe non-toxic haemagluttinin and/or non-toxic non-haemagluttinin proteincomponents of the complex. The 150 kDa botulinum toxin molecule is alsoreferred to as the neurotoxic component and as pure botulinum toxin.

An excipient that can be present in a botulinum toxin pharmaceuticalcomposition can be a protein such as an albumin, such as a human serumalbumin or a recombinantly made albumin. Another excipient that can bepresent in a botulinum toxin pharmaceutical composition can be sodiumchloride. Albumin and sodium chloride can be used as stabilizingexcipients in a botulinum toxin pharmaceutical composition. It is knownto use of sodium chloride and albumin as bulking agents in a botulinumtoxin pharmaceutical composition. The albumin is used as an excipient tostabilize the toxin during drying and to prevent the toxin from adheringto surfaces, such as the glass surfaces onto which the toxin can comeinto contact during manufacture and storage. See e.g., Rader R. A.,Botulinum toxin A, in Ronald Rader, ed. BIOPHARMA: BiopharmaceuticalProducts in the U.S. Market Rockville, Md.: Biotechnology InformationInstitute; 2001:pp. 271-274 (332), and; Rader R. A., Botulinum toxin B,in Ronald Rader, ed. BIOPHARMA: Biopharmaceutical Products in the U.S.Market Rockville, Md.: Biotechnology Information Institute; 2001:pp.274-276 (333).

An embodiment of my invention is a botulinum toxin pharmaceuticalcomposition with particular ratios of the albumin to the sodium chloridepresent in a botulinum toxin pharmaceutical compositions. I have foundthat such ratios permit a significantly increase in the potency of areconstituted lyophilized or vacuum dried botulinum toxin pharmaceuticalcomposition.

There are a number of reasons why it would not be expected that alteringa ratio of excipients present in a botulinum toxin pharmaceuticalcomposition would increase the potency of the botulinum toxin, and whyone would expect just the opposite to occur.

First, botulinum toxin is a relatively large protein for incorporationinto a pharmaceutical formulation (the molecular weight of the botulinumtoxin type A complex is 900 kD) and is therefore is inherently fragileand labile. The size of the toxin complex makes it much more friable andlabile than smaller, less complex proteins, thereby compounding theformulation and handling difficulties if toxin stability is to bemaintained. Hence, altering a ratio of excipients present in a botulinumtoxin pharmaceutical composition would be expected to denature, fragmentor otherwise detoxify the toxin molecule or cause disassociation of thenon-toxin proteins present in the toxin complex.

Second, as the most lethal known biological product, exceptional safety,precision, and accuracy is called for at all steps of the formulation ofa botulinum toxin containing pharmaceutical composition. Thus, alteringa ratio of excipients present in a botulinum toxin pharmaceuticalcomposition would be expected to exacerbate or to interfere with thealready extremely stringent botulinum toxin containing pharmaceuticalcomposition formulation requirements.

Third, since botulinum toxin was the first microbial toxin to beapproved (by the FDA in 1989) for injection for the treatment of humandisease, specific protocols had to be developed and approved for theculturing, bulk production, formulation into a pharmaceutical and use ofbotulinum toxin. Important considerations are toxin purity and dose forinjection. Hence, altering a ratio of excipient present in a botulinumtoxin pharmaceutical composition would be expected to interfere withtoxin purity and dosage requirements.

Fourth, particular difficulties exist to stabilize botulinum toxin typeA, because type A consists of a toxin molecule of about 150 kD innoncovalent association with nontoxin proteins weighing about 750 kD.The nontoxin proteins are believed to preserve or help stabilize thesecondary and tertiary structures upon which toxicity is dependant.Procedures or protocols applicable to the stabilization of nonproteinsor to relatively smaller proteins are not applicable to the problemsinherent with stabilization of the botulinum toxin complexes, such asthe 900 kD botulinum toxin type A complex. Thus while from pH 3.5 to 6.8the type A toxin and non toxin proteins are bound togethernoncovalently, under slightly alkaline conditions (pH>7.1) the verylabile toxin is released from the toxin complex. As set forthpreviously, pure botulinum toxin (i.e. the 150 kD molecule) has beenproposed as the active ingredient in a pharmaceutical composition. Thus,altering a ratio of excipient present in a botulinum toxinpharmaceutical composition would be expected to upset this fragile toxinstability equilibrium.

I found that within certain ranges when albumin concentrations wereincreased as compared to the sodium chloride concentration, the potencyof the reconstituted botulinum toxin pharmaceutical compositionincreased. I also found that within certain ranges when sodium chlorideconcentrations were increased as compared to the albumin concentration,the potency of the reconstituted botulinum toxin pharmaceuticalcomposition decreased. Surprisingly, a high (absolute) concentrations ofsodium chloride were found to not be deleterious to potency afterreconstitution as long as a certain ratio of the sodium chloride to thealbumin was maintained. Thus, I discovered that there exist optimalsodium chloride to albumin ratios (irrespective of the absolute amountsof sodium chloride or of albumin present) at which an increased potencyof the botulinum toxin pharmaceutical composition after reconstitutioncan be obtained.

As set forth above, I have discovered that establishing particularsodium chloride to albumin ratios in a botulinum toxin pharmaceuticalcomposition prior to lyophilization or freeze drying can be used tooptimize the potency of the reconstituted botulinum toxin pharmaceuticalcomposition.

Significantly, I also discovered that reconstitution of the botulinumtoxin pharmaceutical composition with normal saline (0.9%), the typicalreconstitution fluid, does not affect the optimization of the potencybotulinum toxin pharmaceutical composition obtaining by establishedcertain sodium chloride to albumin ratios in the botulinum toxinpharmaceutical composition prior to its lyophilization or freeze drying.This discovery therefore permits conservation of the tonicity of thereconstituted botulinum toxin pharmaceutical composition administered toa patient,

Without wishing to be bound by theory, it can be hypothesized thatestablishment of certain sodium chloride to albumin ratios in thebotulinum toxin pharmaceutical composition prior to its lyophilizationor freeze drying permits obtaining an optimized potency of the botulinumtoxin pharmaceutical composition after it's reconstitution by providinga hospitable chemical and physical environment for the botulinum toxinduring the processing (compounding or formulation) steps or procedureswhile also reducing adsorption of the botulinum toxin upon contactsurfaces (such as glass vials). Presumably, processing of a botulinumtoxin pharmaceutical composition with non-optimized ratios of sodiumchloride and albumin damages the botulinum toxin molecule and increasesit's adsorption to surfaces.

Thus, changing the NaCl/HSA ratio to a particular ratio may increasetoxin potency because less toxin is thereafter lost during freezing todenaturation and adsorption to surfaces (these two phenomenon may berelated, e.g., denaturation caused by adsorption). HSA can act as acryoprotectant and NaCl as a degradant. Typically, some amount of abotulinum toxin will adhere to glass surface. I have determined thatwhen less NaCl is present in a botulinum toxin pharmaceuticalcomposition, the vacuum-dried toxin does not adhere to a glass surface,thereby indicating that NaCl can facilitate or cause adsorption of thetoxin to processing or storage surfaces. Thus particular HSA:NaCl ratioscan be optimal because they permit the HSA to provide sufficientcryoprotection while at the same time counteracting a deleterious effect(surface adsorption) caused by of the NaCl present.

Thus, my discovery permits a botulinum toxin pharmaceutical compositionto be made with a potency that is essentially 100% of the theoreticallypossible potency. Additionally the optimized potency is maintained afterreconstitution with saline, which permits administration of an isotonicbotulinum toxin pharmaceutical composition. The result is a moreefficient manufacturing use of the botulinum toxin active ingredient anda reduced patient exposure to degraded botulinum toxin in the finalbotulinum toxin pharmaceutical composition.

A significant advantage of my invention is that it permits a botulinumtoxin pharmaceutical composition to be manufactured (compounded from araw or bulk botulinum toxin) with considerably less botulinum toxin.This permits a more efficient manufacturing process in which less bulktoxin is used to make the final botulinum toxin pharmaceuticalcomposition. Additionally, because the final botulinum toxinpharmaceutical composition contains less botulinum toxin, the patient,on a unit to unit basis, is administered less botulinum toxin with theensuing advantages of fewer side effects, such as reducedimmunogenicity. Specifically, my invention permits a botulinum toxinpharmaceutical composition to be made with the same potency but withfrom about 5% less to about 50% less total botulinum toxin present inthe botulinum toxin pharmaceutical composition. For example, a botulinumtoxin pharmaceutical composition which formerly comprised about 20 unitsof botulinum toxin for each 1 ng of botulinum toxin present can,according to my invention, now be made with as much as 40 units ofbotulinum toxin for each 1 ng of botulinum toxin present in thebotulinum toxin pharmaceutical composition.

A botulinum toxin pharmaceutical composition manufacturing (compounding)process can typically require as much as a 50% overage, meaning that themanufacturing process which is initiated with a 1.5× amount (i.e. 150units) of a botulinum toxin provides a botulinum toxin pharmaceuticalcomposition with an amount 1× (i.e. 100 units) of the botulinum toxin. Amanufacturing or compounding process is the process by which a botulinumtoxin (referred to as bulk or raw toxin) obtained from bacterialfermentation is then diluted, compounded and processed for thepreparation of a botulinum toxin pharmaceutical composition suitable foradministration to humans for therapeutic and/or cosmetic purposes.

Thus, there is an unexplained loss of up to 50% of the potency of thebotulinum toxin during the compounding process. It has been postulatedthat the 50% overage is required due to denaturation and/or loss ofbotulinum toxin during the compounding process. My invention indicatesthat the up to 50% overage of botulinum toxin is not lost duringcompounding, but rather the chemical composition of the formulation isthe critical parameter in achieving full recovery of toxin in thefinished product. No overage is necessary when optimized ratios of theexcipients are used by providing the appropriate environment during thevacuum-drying process. While not wanting to be bound by theory, it isplausible that optimal ratios reduce adsorption to surfaces anddenaturation during the drying process.

Thus, my invention permits a botulinum toxin pharmaceutical compositionto be made with eg from about 34% less (if the amount of botulinum toxinin a 100 unit vial is reduced from 3.8 ng to 2.5 ng) to about 48% less(if the amount of toxin in a 100 unit vial is reduced from 4.8 ng to 2.5ng, to about to about 50% less (if the amount of toxin in a 100 unitvial is reduced from 5.0 ng to 2.5 ng.

Human serum albumin (plasma derived) is available commercially fromvarious sources, including, for example, from Bayer Corporation,pharmaceutical division, Elkhart, Ill., under the trade name Plasbumin®.Plasbumin® is known to contain albumin obtained from pooled human venousplasma as well as sodium caprylate (a fatty acid, also known asoctanoate) and acetyltryptophan (“NAT”). See e.g. the BayerPlasbumin®-20 product insert (directions for use) supplied with theproduct and as published athttp://actsysmedical.com/PDF/plasbumin20.pdf. The caprylate andacetyltryptophan in commercially available human serum albumin areapparently added by FDA requirement to stabilize the albumin duringpasteurization at 60 degrees C. for 10 hours prior to commercial sale.See e.g. Peters, T., Jr., All About Albumin Biochemistry, Genetics andMedical Applications, Academic Press (1996), pages 295 and 298.Recombinant human albumin is available from various sources, includingfor example, from Bipha Corporation of Chitose, Hokkaido, Japan, WelfideCorporation of Osaka, Japan, and from Delta Biotechnology, Nottingham,U.K., as a yeast fermentation product, under the trade name Recombumin®.

It is known to express recombinant human serum albumin (rHSA) in theyeast species Pichia pastoris. See e.g. Kobayashi K., et al., Thedevelopment of recombinant human serum albumin, Ther Apher 1998November; 2(4):257-62, and; Ohtani W., et al., Physicochemical andimmunochemical properties of recombinant human serum albumin from Pichiapastoris, Anal Biochem 1998 Feb. 1; 256(1):56-62. See also U.S. Pat. No.6,034,221 and European patents 330 451 and 361 991. A clear advantage ofa rHSA is that it is free of blood derived pathogens.

The excipient ratios set forth herein can it is believed help to providestability to a neurotoxin active ingredient, such as a botulinum toxin,present in the pharmaceutical composition by: (1) reducing adhesion(commonly referred to as “stickiness”) of the botulinum toxin tosurfaces, such as the surfaces of laboratory glassware, vessels, thevial in which the pharmaceutical composition is reconstituted and theinside surface of the syringe used to inject the pharmaceuticalcomposition. Adhesion of the botulinum toxin to surfaces can lead toloss of botulinum toxin and to denaturation of retained botulinum toxin,both of which reduce the toxicity of the botulinum toxin present in thepharmaceutical composition; (2) reducing the denaturation of thebotulinum toxin and/or dissociation of the botulinum toxin from othernon-toxin proteins present in the botulinum toxin complex, whichdenaturation and/or dissociation activities can occur because of the lowdilution of the botulinum toxin present in the pharmaceuticalcomposition (i.e. prior to lyophilization or vacuum drying) and in thereconstituted pharmaceutical composition; (3) reducing loss of botulinumtoxin (i.e. due to denaturation or dissociation from non-toxin proteinsin the complex) during the considerable pH and concentration changeswhich take place during preparation, processing and reconstitution ofthe pharmaceutical composition.

The three types of botulinum toxin stabilizations presumably provided bythe ratios set forth herein can conserve and preserve the botulinumtoxin with it native toxicity prior to injection of the pharmaceuticalcomposition.

In certain embodiments of the invention, the pharmaceutical compositionsof the invention may comprise a plurality of botulinum toxin serotypes.In other words, the composition may include two or more differentbotulinum toxin serotypes. For example, a composition may includebotulinum toxin serotypes A and B. In another embodiment, a compositionmay include botulinum toxin serotypes A and E. Using a combination ofbotulinum toxin serotypes will permit caregivers to customize thecomposition to achieve a desired effect based on the condition beingtreated. In an additional embodiment of the invention, the compositionmay comprise a modified botulinum toxin. The modified botulinum toxinwill preferably inhibit the release of neurotransmitter from a neuron,but may have a greater or lower potency than the native botulinum toxin,or may have a greater or lower biological effect than the nativebotulinum toxin. Because the compositions of the invention may be usedfor relatively long-term treatment of animals, the compositions may beprovided in a relatively pure form. In one embodiment, the compositionsare of a pharmaceutical grade. In certain embodiments, the clostridialneurotoxin has a greater than 95% purity. In additional embodiments, theclostridial neurotoxin has a purity greater than 99%.

My invention also encompasses addition of a preservative, either in thediluent or formulation itself, to allow extended storage. A preferredpreservative is preserved saline containing benzyl alcohol.

A liquid formulation can be advantageous. A single-step presentation(e.g., pre-filled syringe) or a product configuration that the userperceives as a single-step presentation (e.g., dual-chambered syringe)would provide convenience by eliminating the reconstitution step.Freeze-drying is a complicated, expensive and difficult process. Liquidformulations are often easier and cheaper to produce. On the other handliquid formulations are dynamic systems and therefore more susceptibleto excipient interaction, fast reactions, bacterial growth, andoxidation than freeze-dried formulations. A compatible preservativemight be needed. Anti-oxidants such as methionine might also be usefulas scavengers especially if surfactants are used to reduce adsorption asmany of these compounds contain or produce peroxides. Any of thestabilizing excipients which can be used in a freeze-dried formulation(e.g., hydroxyethyl starch or an amino acid such, lysine) might beadapted to use in a liquid formulation to assist in reducing adsorptionand stabilize the toxin. Suspensions similar to those developed forinsulin are also good candidates. Additionally, stabilizing botulinumtoxin in a liquid vehicle might require a low pH vehicle as the toxin isreported to be labile above pH 7. This acidity could produce burning andstinging upon injection. A binary syringe could be employed. Inclusionof a co-dispensed buffer, sufficient to raise the pH to physiologiclevels, would alleviate injection discomfort of a low pH whilemaintaining the toxin at a low pH during storage. Another dual-chamberedsyringe option would include diluent and lyophilized material segregatedin separate chamber, only mixing upon use. This option provides theadvantages of a liquid formulation without the additional resources andtime.

As discussed herein, the neurotoxin may be prepared and purified usingtechniques well-known in the art. The purified toxin may subsequently bediluted in a stabilizer such as a polysaccharide (e.g., hetastarch), ora recombinant serum albumin, or a serum albumin of the species of animalreceiving the neurotoxin. It is preferred that the stabilizer preventsor reduces denaturation of the toxin, and produces no, or minimal,immunogenic responses in the animal that will receive the toxin.Aliquots of the diluted toxin are then lyophilized using conventionalprocedures.

The lyophilized neurotoxin may be reconstituted before administering theneurotoxin to a subject by adding water, saline, or any buffer solutionto the lyophilized neurotoxin. In certain embodiments, sodium freebuffers may be preferred to help reduce denaturation of the neurotoxin.

The pharmaceutical compositions of the invention can be administeredusing conventional modes of administration. In preferred embodiments ofthe invention, the compositions are administered intramuscularly orsubcutaneously to the subject. In other embodiments, the compositions ofthe invention may be administered intrathecally. In addition, thecompositions of the invention may be administered with one or moreanalgesic or anesthetic agents.

The most effective mode of administration and dosage regimen for thecompositions of this invention depends upon the type, severity, andcourse of the condition being treated, the animal's health and responseto treatment, and the judgment of the treating doctor. Accordingly, themethods and dosages of the compositions should be tailored to theindividual subject.

The compositions of the invention may also be injected into smoothmuscles (as compared to striated muscles) to treat colonic, bladder,esophageal, or gastrointestinal dysfunction, including, but not limitedto achalasia, anal fissure, hyperactive sphincter of oddi. Theadministration of the compositions may reduce or prevent unfavorablesystemic consequences from treatment with drugs that do not specificallyact on the organ of interest.

Compositions containing botulinum toxin may be administeredintramuscularly, intrathecally, or subcutaneously to relieve painexperienced by the animal. These treatments are also restricted to thesite of injection and have minimal side effects compared to currentsystemic approaches of treating these pain syndromes with pain relievingdrugs.

Relief from pain by practicing the methods of the invention may bedetermined by observing the reduction in the number of symptoms that theanimal is exhibiting. One or more of the symptoms may be reduced.

As indicated above, dosages of the neurotoxin, such as botulinum toxin,in the compositions may vary. In one embodiment, the compositionscontain a therapeutically effective amount of neurotoxin, for example,between about 1 U and about 500 U of botulinum toxin type A. Preferablythe amounts are between about 10 U and about 300 U. More preferably theamount is between about 20 U and 250 U, such about 50 U to 200 U, or 70U.

Alternatively, botulinum toxin, such as botulinum toxin type A, can beadministered in amounts between about 10⁻³ U/kg and about 60 U/kg toalleviate pain experienced by a mammal. Preferably, the botulinum toxinused is administered in an amount of between about 10⁻² U/kg and about50 U/kg. More preferably, the botulinum toxin is administered in anamount of between about 10⁻¹ U/kg and about 40 U/kg. Most preferably,the botulinum toxin is administered in an amount of between about 1 U/kgand about 30 U/kg. In a particularly preferred embodiment of the presentdisclosed methods, the botulinum toxin is administered in an amount ofbetween about 1 U/kg and about 20 U/kg.

Compositions containing other serotypes of botulinum toxin may containdifferent dosages of the botulinum toxin. For example, botulinum toxintype B may be provided in a composition at a greater dose than acomposition containing botulinum toxin type A. In one embodiment of theinvention, botulinum toxin type B may be administered in an amountbetween about 1 U/kg and 150 U/kg. Botulinum toxin type B may also beadministered in amounts of up to 20,000 U (mouse units, as describedabove). In another embodiment of the invention, botulinum toxin types Eor F may be administered at concentrations between about 0.1 U/kg and150 U/kg. In addition, in compositions containing more than one type ofbotulinum toxin, each type of botulinum toxin can be provided in arelatively smaller dose than the dose typically used for a singlebotulinum toxin serotype. The combination of botulinum toxin serotypesmay then provide a suitable degree and duration of paralysis without anincrease in diffusion of the neurotoxins (e.g. see U.S. Pat. No.6,087,327).

The compounding process used in the preparation of Botox® (a vacuumdried powdered pharmaceutical composition) begins with the entry ofabout 150 units of the bulk botulinum toxin into the compoundingprocess. The final product (ready for reconstitution) comprises onlyabout 100 units of the botulinum toxin (as well as specific amount ofalbumin and sodium chloride as excipients added during the compoundingprocess). Thus, about 50 units of botulinum toxin (about one third ofthe amount of the botulinum toxin which entered into the compoundingprocess) is lost during compounding, for example by denaturation,absorption and inactivation of the botulinum toxin onto processingsurfaces. Hence, it has been necessary to start the compounding processwith about a 50% overage (i.e. start with about 150 units of botulinumtoxin in order to obtain product with about 100 units of botulinumtoxin).

One hundred units of botulinum toxin typically comprises from about 3.6ng to about 5 ng of botulinum toxin. I have discovered that by alteringthe ratio of the albumin and sodium chloride excipients used in thecompounding process it is possible to: (1) remove the 50% overagefactor, and; (2) on a nanogram to nanogram basis, obtain a more potentbotulinum toxin. By eliminating the 50% overage factor in thecompounding process, one can have about 100 units of botulinum toxinenter the compounding process and yet at the completion of thecompounding process still obtain product with about 100 units ofbotulinum toxin. Additionally, one can obtain a 100 botulinum toxin unitproduct comprising only about 2.4 ng of botulinum toxin, as compared tothe previously required 3.6 to 5 ng of botulinum toxin required toobtain a 100 unit botulinum toxin product. Thus, the potency of thebotulinum toxin which was previously as low as about 20 units per ng(100 units divided by 5 ng) can now be increased to as high as about 42units per ng (100 units divided by 2.4 ng), which equates to an increaseof potency of about 110%.

Commercially available botulinum toxin pharmaceutical compositionsapproved by regulatory agencies for use in humans to treat one or moreindications include BOTOX® (Allergan, Inc, Irvine, Calif.), Dysport®(Ipsen Pharmaceuticals, Paris, France) and MyoBIoc™ (SolsticeNeurosciences, San Diego, Calif.).

EXAMPLES

The following non-limiting examples provide those of ordinary skill inthe art with specific preferred formulations and methods and are notintended to limit the scope of the invention.

In the Examples below the well known mouse lethal dose₅₀ assay (the“MLD50”) was used to determine recovered potency of the botulinum toxinformulations made. The MLD50 is a method for measuring the potency of abotulinum toxin by intraperitoneal injection of the botulinum toxin intofemale mice (about four weeks old) weighing 17-22 grams each at thestart of the assay. Each mouse is held in a supine position with itshead tilted down and is injected intraperitoneally into the lower rightabdomen at an angle of about 30 degrees using a 25 to 27 gauge ⅜″ to ⅝″needle with one of several serial dilutions of the botulinum toxin insaline. The death rates over the ensuing 72 hours for each dilution arerecorded. The dilutions are prepared so that the most concentrateddilution produces a death rate of at least 80% of the mice injected, andthe least concentration dilution produces a death rate no greater than20% of the mice injected. There must be a minimum of four dilutions thatfall within the monotone decreasing range of the death rates. Themonotone decreasing range commences with a death rate of no less than80%. Within the four or more monotone decreasing rates, the two largestand the two smallest rates must be decreasing (i.e. not equivalent). Thedilution at which 50% of the mice die within the three day postinjection observation period is defined as a dilution which comprisesone unit (1 U) of the botulinum toxin.

In the Tables which follow “normalized” means with regard to the amountused in a 100 unit vial of Botox®.

Example 1 High Potency Botulinum Toxin Formulations (Research Method)With Various Ratios of Sodium Chloride to Albumin

An experiment was carried out to assess the recovered potency ofnumerous botulinum toxin research vial formulations with the same amountof botulinum toxin type A complex in each formulation, but withdifferent amounts of HSA and NaCl present in the each formulation. Thus,while 2.5 ng of the botulinum toxin was used consistently per vial, eachformulation vial contained from 0N (0 μg) of HSA to 10N (5000 μg) ofHSA, and from 0N (0 μg) of NaCl to 10N (9000 μg) of NaCl.

The data in Table 1 was obtained using research lot preparationprocedures. Thus, the Table 1 data was obtained by mixing one of thespecified seven different amounts of sodium chloride (NaCl) (from a 0.1N amount of 90 μg per vial to a 10N amount of 9000 μg per vial) with oneof the specified three different amounts of human serum albumin (HSA)(Bayer) (from a 0.5N amount of 250 μg per vial to a 1N amount of 500 μgper vial) with sterile water and the same amount (2.5 ng/vial) ofbotulinum toxin type A complex so as to prepare experimental or researchbotulinum toxin pharmaceutical composition vials. These vials were thenplaced in a lyophilizer, vacuum-dried and stoppered. The vials were thenreconstituted with normal saline and tested for recovered potency usinga refined version of the mouse potency LD50 assay.

Significantly, Table 1 shows that, as compared to the Botox® equivalentresearch formulation (that is, the research vial formulation whichcontained 500 μg of HSA, 900 μg of NaCl and 2.5 ng of botulinum toxintype A complex, and had a recovered potency of 57 units)), a highpotency (61 to 89 units of botulinum toxin activity per vial, that isfrom 107% to 156% greater than the potency of the Botox® equivalentresearch formulation) was obtained for each of the six formulationswhich had HSA:NaCl ratios greater than 0.6 (the HSA: NaCl ratios inTable 1 that were greater than 0.6 were ratios from 0.7 to 5.6.

The Table 1 data therefore shows that a high potency botulinum toxinformulation can be obtained by increasing the HSA:NaCl ratio of theformulation.

TABLE 1 Potency of Botulinum Toxin Formulations with HSA:NaCl Ratiosfrom 0.03 to 5.6 Normalized Normalized HSA (μg/vial) NaCl (μg/vial) 0.5(250) 0.75 (375) 1 (500) 0.1 (90)  81 (2.8) 74 (4.2) 89 (5.6)  0.5 (450)49 (0.6) 68 (0.8) 64 (1.1) 0.75 (675)  45 (0.4) 60 (0.6) 61 (0.7)  1(900) 44 (0.3) 52 (0.4) 57 (0.6)   2 (1800) 49 (0.1) 56 (0.2) 62 (0.3)  5 (4500)  41 (0.06)  46 (0.08) 59 (0.1)  10 (9000)  49 (0.03)  48(0.04)  58 (0.06)

A further example showing the potency of reconstituted researchformulations made according to the procedures set forth in this Example1 is provided by Table 2 below and by FIG. 2. Table 2 shows thatformulations which contained a constant 1N (500 μg) amount of HSA, 2.5ng of botulinum toxin and amounts of NaCl which varied from zero to 10N(9000 μg) had a potency which did not vary significantly as the HSA:NaClratio was decreased below 0.6, but that the potency of the formulationincreased from about 57 units to about 90 units, as the HSA:NaCl ratiowas increased from 0.6 to about 5.6.

TABLE 2 Potency of Botulinum Toxin Formulations with 1N and HSA:NaClRatios from 0.06 to 5.6 Normalized Amount of NaCl HSA:NaCl ratio Potency10 0.06 59 5 0.1 60 2 0.3 61 1 0.6 58 0.75 0.7 62 0.5 1.1 65 0.1 5.6 89

FIG. 2 is a graphical representation of the Table 2 data.

FIG. 3 presents a combined view in three axes of the data generated bythis Example 1. FIG. 3 shows that as the HSA:NaCl ratio is increasedbeyond about 0.6 (by either: (a) holding the amount of HSA in theformulation constant [at an amount between 0 and 10N] and decreasing theamount of NaCl in the formulation [from 10N to 0], or by; (b) holdingthe amount of NaCl constant and increasing the amount of HSA in theformulation), generally the recovered potency of the formulationincreases. The amount of botulinum toxin in all the formulations used togenerate the FIG. 3 data was constant at 2.5 ng per vial.

Example 2 High Potency Botulinum Toxin Formulations (Commercial Method)With Particular Ratio of Sodium Chloride to Albumin

A further experiment was carried out in which botulinum toxinpharmaceutical compositions were made (compounded) using botulinum toxintype A complex, sodium chloride and human serum albumin. Botulinum toxinpharmaceutical compositions containing differing ratios of sodiumchloride to the HSA were compounded using commercial manufacturing lotprocedures. The compositions were then either lyophilized and vacuumdried to a solid, powder) state, followed by reconstitution with salineand mouse LD₅₀ recovered potency evaluation.

Results obtained are set forth in Table 3. The Table 3 data was obtainedas follows: for the BOTOX data (last row in Table 3) 100 units vials ofBotox® were reconstituted with normal saline followed by use of themouse LD₅₀ assay to measure potency. The 1N HSA, 2N HSA, 5N HSA and 10NHSA represent formulations compounded in the same way used for themanufacture of Botox® and with the same excipients, reconstituted in thesame manner, and potency assessed using the same mouse LD₅₀ assay, withonly the following changes:

(1) one (1N), two (2N), five (5N) or ten times (10N) as much HSA wasused in the compounding process for the manufacture of these fourbotulinum toxin type A complex formulations, as compared to how much HSAis used in the manufacture of Botox®. Thus, as shown in Table 3, the 1N(1 N meaning normalized to contain the same amount of that excipient asis present in a 100 unit vial of Botox®) formulation was compounded tocontain 500 μg of HSA, while the 10N formulation was compounded tocontain 5000 μg of HSA.

(2) the amount of botulinum toxin type A complex used in each of thefour 1N HSA, 2N HSA, 5N HSA and 10N HSA formulations was 2.4 ng.

(3) the amount of sodium chloride used in the compounding process forthe manufacture of each of the four botulinum toxin type A complexformulations was altered so as to provide, a constant weight to weightratio the HSA to the NaCl in the formulation of 28. Thus, in each ofthese four formulations the HSA:NaCl ratio was 47 times what it is forBotox® (28 vs 0.6).

Significantly, Table 3 shows that a high potency (95 to 103 units ofbotulinum toxin activity per vial) was obtained for each of the fourHSA:NaCl ratio of 28 botulinum toxin formulations, and that this highpotency was obtained upon use of from about 33% to about 52% lessbotulinum toxin (as compared to use of from about 3.6 ng to about 5 ngof botulinum toxin per vial of Botox®).

Additionally, as shown by Table 3, through wide ranges of the absoluteamounts of HSA and sodium chloride present, a weight to weight ratio ofHSA to sodium chloride of 28 consistently permitted a potency of about40 units per ng of the compounded and reconstituted botulinum toxin tobe obtained.

TABLE 3 Potency of Botulinum Toxin Formulations with an HSA:NaCl ratioof 28 HSA:NaCl Toxin NaCl HSA Potency Wt. Ratio (ng/vial) (μg/vial)(μg/vial) (n = 2)  1N HSA 28 2.4 18 500 96  2N HSA 28 2.4 36 1000 103 5N HSA 28 2.4 90 2500 98 10N HSA 28 2.4 180 5000 95 BOTOX 0.6 3.6 to 5900 500 70-100

Thus, this experiment showed that the manufacturing (compounding)process 50% overage can be eliminated by altering the composition ratioof the formulation while still using existing manufacturing processesand excipients

A pharmaceutical composition according to the invention disclosed hereinhas many advantages, including that the pharmaceutical composition canhave high stability and high % recovery of toxin potency comparable toor superior to that achieved with currently available pharmaceuticalcompositions.

Various publications and/or references have been cited herein, thecontents of which, in their entireties, are incorporated herein byreference.

Although the present invention has been described in detail with regardto certain preferred methods, other embodiments, versions, andmodifications within the scope of the present invention are possible.For example, a wide variety of stabilizing polysaccharides, proteins andamino acids are within the scope of the present invention.

Accordingly, the spirit and scope of the following claims should not belimited to the descriptions of the preferred embodiments set forthabove.

1. A lyophilized pharmaceutical composition comprising: (a) betweenabout 2.0×10⁻¹¹ grams and about 3.5×10⁻¹¹ grams of a botulinum toxintype A for each unit of botulinum toxin present in the pharmaceuticalcomposition, the unit of the botulinum toxin being determined by a mouseLD50 potency assay; (b) an albumin, and (c) a polysorbate, (d) whereinthe composition components are mixed and lyophilized, and the weight toweight ratio of the albumin to the polysorbate present in thepharmaceutical composition is greater than 0.6 and less than about 100.2. The pharmaceutical composition of claim 1, wherein the botulinumtoxin is present as a botulinum toxin complex.
 3. The pharmaceuticalcomposition of claim 1, wherein the botulinum toxin is present as a purebotulinum toxin.
 4. The pharmaceutical composition of claim 1, whereinthe albumin is a serum albumin.
 5. The pharmaceutical composition ofclaim 1, wherein the albumin is a recombinant albumin.
 6. Thepharmaceutical composition of claim 5, wherein the botulinum toxin ispresent as a botulinum toxin complex.
 7. The pharmaceutical compositionof claim 5 wherein the botulinum toxin is present as a pure botulinumtoxin.
 8. A lyophilized pharmaceutical composition, comprising: (a) abotulinum toxin; (b) a polysorbate, and; (c) an albumin; wherein thecomposition components are mixed and lyophilized, and the potency of thebotulinum toxin present in the pharmaceutical composition is betweenabout 24 units/ng and about 60 units/ng, and further wherein the weightto weight ratio of the albumin to the polysorbate is greater than 0.6and less than about
 100. 9. The pharmaceutical composition of claim 8,wherein the albumin is a serum albumin.
 10. The pharmaceuticalcomposition of claim 8, wherein the albumin is a recombinant albumin.11. A lyophilized pharmaceutical composition, comprising: (a) abotulinum toxin; (b) a polysorbate, and; (c) an albumin; wherein thecomposition components are mixed and lyophilized, and the weight toweight ratio of the albumin to the polysorbate present in thepharmaceutical composition is between about 1 and about 40 and thepotency of the botulinum toxin present in the pharmaceutical compositionis between about 24 units/ng and about 60 units/ng.